Among the ophthalmic apparatuses, the major ones are those which use optical coherence tomography (OCT) to acquire tomographic images of a fundus of a subject's eye at high resolution, and scanning laser ophthalmoscopes (SLO).
Japanese Patent Application Laid-Open No. 2009-291252 discusses a technique in which an examiner performs alignment with respect to a subject's eye using a joystick while observing an observation image of an anterior eye portion of the subject's eye on a monitor, and, after completion of the alignment, obtains an SLO fundus image. At this time, by pressing an auto-focusing start switch, the examiner can move a focus lens disposed in an SLO optical system based on the SLO fundus image. After the focus lens disposed in the SLO optical system is moved, a focus lens disposed in an OCT optical system is moved based on the SLO fundus image to perform rough auto-focusing in the OCT optical system. A reference mirror is then moved based on an OCT tomographic image to automatically adjust a coherence gate and to perform precise auto-focusing in the OCT optical system.
Japanese Patent Application Laid-Open No. 2010-181172 also discusses a technique in which an examiner moves a fundus camera unit toward a subject by operating a control lever, and switches an image on a display screen from an image of an anterior eye portion of the subject's eye to an observation image of a fundus thereof to adjust alignment. In this technique, after the image is switched, the examiner turns on an alignment light source to project alignment bright points onto the subject's eye. After the alignment adjustment is complete, the examiner adjusts focusing. Then, upon a determination that a proper alignment state has been achieved, luminance values of an OCT tomographic image obtained by moving a reference mirror are analyzed to automatically detect the OCT tomographic image. In Japanese Patent Application Laid-Open No. 2010-181172, the alignment adjustment may be performed manually or automatically.